Page 116 - Modelling in Transport Phenomena A Conceptual Approach

96 CHAPTER 4. EVALUATION OF TRANSFER COEFFICIENTS

4.5.1.3 Solutions to the engineering problems

I. Laminar flow

For flow in a pipe, the Reynolds number is defined by

4 PQ
Re = =- (4.510)
TPD
Substitution of Eq. (4.510) into Eq. (4.57) yields
4 npD
f=- (4.5-11)
PQ

Calculate lAPl or @; given Q and D
Substitution of Eq. (4.511) into Eq. (4.56) gives

(4.512)

The pump size can be calculated from Eq. (4.52) as

(4.5-13)

H Calculate Q; given lAPl and D
Rearrangement of Eq. (4.5-12) gives

lQ= 128pL I (4.514)
lap'

Calculate D; given Q and lAPl
Rearrangement of Eq. (4.512) gives

(4.515)